An electronic device in a wireless power system may be operable with a removable accessory such as a case. The device may convey wireless power to, from, or through the case while the device is coupled to the case. The device may have coplanar power transmitting and power receiving coils. The removable accessory may have an embedded switchable ferrimagnetic core and a coil that overlaps the switchable ferrimagnetic core. The switchable ferrimagnetic core may be operable in a first state where the switchable ferrimagnetic core is unsaturated. The switchable ferrimagnetic core may be operable in a second state where the switchable ferrimagnetic core is saturated by a magnetic field from a permanent magnet in a wireless power transmitting device. In the second state, the switchable ferrimagnetic core may have a lower magnetic permeability and higher magnetic reluctance than in the first state.

The magnetic component comprises: a magnetic core comprising an E-shaped lower part, an E-shaped upper part and an I-shaped central part closing both the lower part and the upper part such that the lower part and the central part define two lower magnetic circuits and the upper part and the central part define two upper magnetic circuits; a first coil and a second coil wound around a central branch of the lower part to be coupled to one another; a third coil wound around a central branch of the upper part, the third coil being connected in series with the second coil. The central part has a reluctance lower than both that of the lower part along each lower magnetic circuit and that of the upper part along each upper magnetic circuit.

A method for making an energy transfer element provides a magnetic core having a gap in a magnetic path, positions in the gap magnetizable material that produces an initial flux density, cures the suspension medium, and wraps one or more power windings around the magnetic path. When the magnetizable material is magnetized, a flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material comprises a mixture of a suspension medium that includes uncured epoxy and magnetizable particles. The magnetizable particles are capable of permanent magnetic properties when magnetized. The particles of magnetic material having magnetic permeability of at least 1000μ.sub.o. The particles of magnetic material that have a magnetic permeability of at least 1000μ.sub.o and the particles of magnetizable particles are uniformly distributed in the suspension medium.

An energy transfer element comprises a U-shaped core of powder core, the U-shaped core having two legs and a gap in a magnetic path, a bar comprising magnetizable material positioned in the gap such that the magnetic core and magnetizable material form a rectangular toroid, and one or more power windings wrapped around the magnetic path. The magnetizable material is capable of being magnetized. When the magnetizable material is unmagnetized, the magnetizable material has an initial flux density. When the magnetizable material is magnetized, the flux density produced by the magnetized material is offset from the initial flux density. The magnetizable material is an unmagnetized magnet or a suspension medium such as epoxy with magnetized magnetizable particles and powder core. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

An energy transfer element comprises a magnetic core having a gap in a magnetic path. Magnetizable material producing an initial flux density is positioned in the gap. One or more power windings is wrapped around the magnetic path. When the magnetizable material is magnetized the flux density produced by the magnetized material is offset from the initial flux density. The core is a toroid magnetic core or is comprised of two core pieces. The magnetizable material is an unmagnetized magnet or a mixture of a suspension medium comprising uncured epoxy and magnetizable particles. The magnetizable particles are selected from a group comprising Neodymium Iron Boron (NdFeB) based materials or Samarium Cobalt (SmCo) based material.

A planar magnetic core includes multiple ferromagnetic layers including multiple hard ferromagnetic bias layers and multiple soft ferromagnetic layers. Each ferromagnetic layer comprises a soft ferromagnetic layer or a hard ferromagnetic bias layer. Each hard ferromagnetic bias layer is a neighboring ferromagnetic layer of at least one soft ferromagnetic layer. The planar magnetic core also includes a plurality of insulating layers, each insulating layer disposed between adjacent ferromagnetic layers. Each ferromagnetic layer has an easy axis of magnetization parallel to a principal plane of the planar magnetic core, where the easy axes of magnetization are aligned. Each hard ferromagnetic bias layer is magnetized to create an in-plane bias magnetic flux through the hard ferromagnetic bias layer in a first direction that is parallel to the easy axis of magnetization and forms a closed path through a neighboring soft ferromagnetic layer in a second direction parallel to the first direction.

An inductive core including a body including a ferromagnetic material and a magnet, the magnet forming a first path for circulating of magnetic flux lines produced by the magnet, and the ferromagnetic material at least partially forming a second path for circulating the magnetic flux lines, wherein the ferromagnetic material extends continuously between the poles of the magnet along the poles of the magnet and makes contact with at least a part of an exterior lateral wall of the magnet extending between its poles.

The present disclosure relates to a charging system and a charging method for an automatic force detection robot for a gas pipeline. The charging system includes a primary charging unit disposed outside the gas pipeline and a secondary charging unit disposed in the gas pipeline, wherein the primary charging unit includes a primary magnetic core and a primary coil wound on the primary magnetic core, the secondary charging unit includes a secondary magnetic core and a secondary coil wound on the secondary magnetic core, the primary magnetic core and the secondary magnetic core form a closed magnetic field line, the primary coil is connected to a power supply, and the secondary coil is connected to a battery of the robot. The charging system has the advantages of simple structure, low cost, convenient use, strong anti-interference capability and high charging efficiency, solves the problem that the cableless automatic force detection robot needs to overcome the shielding of the pipeline wall when charging, and improves the capability of the cableless automatic force detection robot when carrying out a long-distance detection in the pipeline. The charging method has the advantages of easy implementation, convenient operation, safety and reliability, and high charging efficiency.

The present disclosure relates to a charging system and a charging method for an automatic force detection robot for a gas pipeline. The charging system includes a primary charging unit disposed outside the gas pipeline and a secondary charging unit disposed in the gas pipeline, wherein the primary charging unit includes a primary magnetic core and a primary coil wound on the primary magnetic core, the secondary charging unit includes a secondary magnetic core and a secondary coil wound on the secondary magnetic core, the primary magnetic core and the secondary magnetic core form a closed magnetic field line, the primary coil is connected to a power supply, and the secondary coil is connected to a battery of the robot. The charging system has the advantages of simple structure, low cost, convenient use, strong anti-interference capability and high charging efficiency, solves the problem that the cableless automatic force detection robot needs to overcome the shielding of the pipeline wall when charging, and improves the capability of the cableless automatic force detection robot when carrying out a long-distance detection in the pipeline. The charging method has the advantages of easy implementation, convenient operation, safety and reliability, and high charging efficiency.

An electromagnetic linear actuator is provided having a housing having a casing section and an end piece, a coil arrangement having two coils which extend about a common axis, are wound in opposite directions and are offset axially from one another, an armature arrangement mounted displacably in the housing along the axis, and a shaft, which passes through the end piece. A magnet arrangement at the end of the shaft has an axially magnetized permanent magnet and two disc-shaped flux conducting pieces are arranged on a front side. The first coil which faces away from the free end of the shaft has a region with a reduced internal diameter. A core of a magnetically active material is held in the coil. In each end positions of the armature arrangement, at least 50% of the axial length of the magnet arrangement is overlapped by one of the coils.